1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
5 Implementation of 1959 Standard Atmosphere added by Tony Peden
8 ------------- Copyright (C) 1999 Jon S. Berndt (jsb@hal-pc.org) -------------
10 This program is free software; you can redistribute it and/or modify it under
11 the terms of the GNU General Public License as published by the Free Software
12 Foundation; either version 2 of the License, or (at your option) any later
15 This program is distributed in the hope that it will be useful, but WITHOUT
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
20 You should have received a copy of the GNU General Public License along with
21 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
22 Place - Suite 330, Boston, MA 02111-1307, USA.
24 Further information about the GNU General Public License can also be found on
25 the world wide web at http://www.gnu.org.
28 --------------------------------------------------------------------------------
30 07/23/99 TP Added implementation of 1959 Standard Atmosphere
31 Moved calculation of Mach number to FGPropagate
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
36 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
38 #ifndef FGAtmosphere_H
39 #define FGAtmosphere_H
41 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
43 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
46 #include <math/FGColumnVector3.h>
48 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
50 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
52 #define ID_ATMOSPHERE "$Id$"
54 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
56 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
60 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
62 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
64 /** Models the standard atmosphere.
65 @author Tony Peden, Jon Berndt
67 @see Anderson, John D. "Introduction to Flight, Third Edition", McGraw-Hill,
68 1989, ISBN 0-07-001641-0
71 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
73 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
75 class FGAtmosphere : public FGModel {
79 FGAtmosphere(FGFDMExec*);
82 /** Runs the Atmosphere model; called by the Executive
83 @return false if no error */
87 /// Returns the temperature in degrees Rankine.
88 inline double GetTemperature(void) const {return *temperature;}
89 /** Returns the density in slugs/ft^3.
90 <i>This function may <b>only</b> be used if Run() is called first.</i> */
91 inline double GetDensity(void) const {return *density;}
92 /// Returns the pressure in psf.
93 double GetPressure(void) const {return *pressure;}
94 /// Returns the standard pressure at a specified altitude
95 double GetPressure(double altitude);
96 /// Returns the standard temperature at a specified altitude
97 inline double GetTemperature(double altitude);
98 /// Returns the standard density at a specified altitude
99 inline double GetDensity(double altitude);
100 /// Returns the speed of sound in ft/sec.
101 inline double GetSoundSpeed(void) const {return soundspeed;}
103 /// Returns the sea level temperature in degrees Rankine.
104 inline double GetTemperatureSL(void) const { return SLtemperature; }
105 /// Returns the sea level density in slugs/ft^3
106 inline double GetDensitySL(void) const { return SLdensity; }
107 /// Returns the sea level pressure in psf.
108 inline double GetPressureSL(void) const { return SLpressure; }
109 /// Returns the sea level speed of sound in ft/sec.
110 inline double GetSoundSpeedSL(void) const { return SLsoundspeed; }
112 /// Returns the ratio of at-altitude temperature over the sea level value.
113 inline double GetTemperatureRatio(void) const { return (*temperature)*rSLtemperature; }
114 /// Returns the ratio of at-altitude density over the sea level value.
115 inline double GetDensityRatio(void) const { return (*density)*rSLdensity; }
116 /// Returns the ratio of at-altitude pressure over the sea level value.
117 inline double GetPressureRatio(void) const { return (*pressure)*rSLpressure; }
118 /// Returns the ratio of at-altitude sound speed over the sea level value.
119 inline double GetSoundSpeedRatio(void) const { return soundspeed*rSLsoundspeed; }
121 /// Tells the simulator to use an externally calculated atmosphere model.
122 void UseExternal(void);
123 /// Tells the simulator to use the internal atmosphere model.
124 void UseInternal(void); //this is the default
125 /// Gets the boolean that tells if the external atmosphere model is being used.
126 bool External(void) { return useExternal; }
128 /// Provides the external atmosphere model with an interface to set the temperature.
129 inline void SetExTemperature(double t) { exTemperature=t; }
130 /// Provides the external atmosphere model with an interface to set the density.
131 inline void SetExDensity(double d) { exDensity=d; }
132 /// Provides the external atmosphere model with an interface to set the pressure.
133 inline void SetExPressure(double p) { exPressure=p; }
135 /// Sets the temperature deviation at sea-level in degrees Fahrenheit
136 inline void SetSLTempDev(double d) { T_dev_sl = d; }
137 /// Gets the temperature deviation at sea-level in degrees Fahrenheit
138 inline double GetSLTempDev(void) const { return T_dev_sl; }
139 /// Sets the current delta-T in degrees Fahrenheit
140 inline void SetDeltaT(double d) { delta_T = d; }
141 /// Gets the current delta-T in degrees Fahrenheit
142 inline double GetDeltaT(void) const { return delta_T; }
143 /// Gets the at-altitude temperature deviation in degrees Fahrenheit
144 inline double GetTempDev(void) const { return T_dev; }
145 /// Gets the density altitude in feet
146 inline double GetDensityAltitude(void) const { return density_altitude; }
148 /// Sets the wind components in NED frame.
149 inline void SetWindNED(double wN, double wE, double wD) { vWindNED(1)=wN; vWindNED(2)=wE; vWindNED(3)=wD;}
151 /// Retrieves the wind components in NED frame.
152 inline FGColumnVector3& GetWindNED(void) { return vWindNED; }
154 /** Retrieves the wind direction. The direction is defined as north=0 and
155 increases counterclockwise. The wind heading is returned in radians.*/
156 inline double GetWindPsi(void) const { return psiw; }
158 inline void SetTurbGain(double tt) {TurbGain = tt;}
159 inline void SetTurbRate(double tt) {TurbRate = tt;}
161 inline double GetTurbPQR(int idx) const {return vTurbPQR(idx);}
162 inline FGColumnVector3& GetTurbPQR(void) {return vTurbPQR;}
171 enum tType {ttStandard, ttBerndt, ttNone} turbType;
172 struct atmType {double Temperature; double Pressure; double Density;};
177 double StdSLtemperature,StdSLdensity,StdSLpressure,StdSLsoundspeed;
178 double rSLtemperature,rSLdensity,rSLpressure,rSLsoundspeed; //reciprocals
179 double SLtemperature,SLdensity,SLpressure,SLsoundspeed;
180 double *temperature, *density, *pressure;
183 double exTemperature,exDensity,exPressure;
184 double intTemperature, intDensity, intPressure;
185 double T_dev_sl, T_dev, delta_T, density_altitude;
187 bool StandardTempOnly;
189 double MagnitudedAccelDt, MagnitudeAccel, Magnitude;
192 FGColumnVector3 vDirectiondAccelDt;
193 FGColumnVector3 vDirectionAccel;
194 FGColumnVector3 vDirection;
195 FGColumnVector3 vTurbulence;
196 FGColumnVector3 vTurbulenceGrad;
197 FGColumnVector3 vBodyTurbGrad;
198 FGColumnVector3 vTurbPQR;
200 FGColumnVector3 vWindNED;
203 /// Calculate the atmosphere for the given altitude, including effects of temperature deviation.
204 void Calculate(double altitude);
205 /// Calculate atmospheric properties other than the basic T, P and rho.
206 void CalculateDerived(void);
207 /// Get T, P and rho for a standard atmosphere at the given altitude.
208 void GetStdAtmosphere(double altitude);
209 void Turbulence(void);
210 void Debug(int from);
213 } // namespace JSBSim
215 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%